Cylinder lock



S. A. LISS CYLINDER LOCK Feb. 9,1937.

Original Filed March 31, 1.933

4 Patented Feb. 9, 1937 CYLINDER LOCK Samuel A. Liss, Philadelphia..1a., assignor to Briggs & Stratton Corporation, Milwaukee,

Wis, a corporation of Delaware Original application March 31, 1933, Serial No. 663,805, now Patent No. 2,003,086, issued May Divided and this application June 29, 1934, Serial No. 733,050

2 Claims.

This invention relates to improvements in. looks and refers more particularly to cylinder locks of the type forming the subject matter of Patent No. 2,003,086, issued May 28, 1935, of which this application is a division.

As in the aforesaid application, it is a general object of this invention to provide a lock having exceptional security against picking and decod- 1118.

More specifically, it is an object of this invention to provide a lock in which the cylinder is secured against movement by an auxiliary locking member or tumbler, or a plurality of such locking members or tumblers, biased to an operative position effecting interengagement between the cylinder and its casing and positively held in such position by any one of the regular key operable tumblers in any but fully retracted position. w

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and more particularly defined by the appended claims, it

being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawing illustrates two complete examples of the physical embodiment of the invention, constructed according to the best modes so far devised for the practical application of the principles thereof, and in which:

Figure 1 is a longitudinal section view through a lock embodying this invention;

Figure 2 is a cross section view taken through Figure 1 on the plane of the line 2-2;

Figure 3 is a longitudinal section view taken through Figure 1 on the plane of the line 33;

Figure '4 is a perspective detail view showing the lock in cross section with the cylinder partially turned irom its locked position to more clearly illustrate the relative position of the various parts;

Figure 5 is a perspective view showing the releasable holding meansat the inner end of the lock for removably securing the cylinder in position;

Figure 6 is an enlarged side view of one of the tumblers employed in the lock, shown in Figures 1 to 4 inclusive;

Figure 7 is a perspective view of one of the auxiliary locking tumblers or looking members;

Figure 8 is a longitudinal section view similar to Figure l, but having a master key inserted therein which is equipped to release the cylinder holding means;

Figure 9 is a longitudinal section view similar to Figure 1, showing a modified embodiment 5 of this invention;

Figure 10 is a view partly in longitudinal section and partly in elevation, taken on the plane of the line i0-i0 of Figure 9;

Figure 11 is a cross section view through Figure 9 on the plane of the line lI-ll; and

Figure 12 is an enlarged perspective view of one of the tumblers used in the modified form of lock shown in Figures 9, l0 and 11.

Referring now more particularly to the accompanying drawing, in which like numerals indicate like parts throughout the several views, the numeral 5 designates the mounting member or casing of the lock, bored as at 6 to receive a lock cylinder i. The cylinder is removably secured in the mounting member or casing by a flange 8 at the front of the cylinder engaging in a counterbore 9, and a releasable retaining member l0 mounted on the inner end of the cylinder and engageable with the adjacent end of the mounting member or casing.

An angle plate H fixed to the inner end of the cylinder to provide means for transmitting rotation to mechanism controlled (not shown), slidably mounts the retaining member, and a spring l2 yieldably urges the same to a position projecting its outer end over the inner edge of the bore 6. This releasable cylinder securing means forms the subject matter of a copending application.

To enable withdrawal and insertion of the cylinder, the retaining member ID may be moved inwardly against the action of its spring 12 by the extended end of a special or master key i3, shown in Figure 8. As shown, the extreme 40 end of the key l3 engages the retaining member and moves the same inwardly against the action of its spring.

The regular key M, shown in Figures 1 and 9, is of insufi'lcient length to engage the re- 45 taining member, so that during normal operation of the lock, the cylinder does not become detached.

To receive the key, the cylinder is equipped with'a keyway [5, which extends inwardly from the front of the cylinder with its bottom opening to the cylindrical surface of the cylinder, although it is to be understood that for the purposes of the invention, the keyway need not break through the cylinder wall. The keyway communicates with a plurality of transverse tumbler receiving recesses or pockets I 8 in which individual key operable tumblers ll are slidably mounted for actuation .by either the special or master key l3, or the regular key M. In the embodiment illustrated in Figures '1 to 4 inclusive, the key operable tumblers are of the pin type, circular in cross section, as specifically shown in Figure 6, whereas in the embodiment illustrated in Figures 9 to 11 inclusive, the tumblers H are of the flat plate type, specifically shown in Figure 12. This is the only diflerence between the two modifications illustrated.

Individual springs I8, confined between the outer ends of the tumblers and a plate l9 embedded in the body of the cylinder across the open tumbler recesses and flush with the cylindrical surface of the cylinder, yieldably project the tumblers inwardly toward -the keyway ii. In the absence of a key, the inner ends of the tumblers rest on the substantially closed bottom of the tumbler recesses or pockets.

The circular pin type. tumblers have their inner ends'pointed or of conical shape to afford proper engagement of the bittings on the key.

It is observed that no portion of the key operable tumblers projects beyond the periphery of the cylinder, the locking engagement between the cylinder and its casing being aflorded by auxiliary tumblers or looking members 20, which are slidable radially in slots 2! formed in the cylinder at right angles to the tumbler recesses or pockets l6 and communicating therewith at their inner edges.

As best shown in Figure '7, these auxiliary tumblers or looking members are substantially in the form of plates with their outer edges reinforced and increased in thickness by reinforcing bindings 22, the outer portions of which provide rounded edges engageable in longitudinal grooves 23 formed in the casing or mounting member and opening to its bore 5.

Projecting from each end of the auxiliary tumblers or looking members are lugs 24, with which springs 25 engage to yielda-bly ur'ge the auxiliary tumblers or looking members outwardly and into their respective grooves 23. The springs 25 are mounted in pockets 26 in the cylinder near the ends of the slots 2i and have their inner ends seated on the bottoms of said pockets and their outer ends bearing against the lugs 2.

When the cylinder is in its normal locked position, which is conveniently indicated by a spring detent 21 carried at the front end portion of the cylinder and engageable in a depression 21' in the casing, the outer edges of the auxiliary tumblers or looking members are projected by the springs 25 into the grooves 23. The distance between the inner edges of the auxiliary tumblers or locking members in this position is just slightly greater than the diameter of the pin tumblers or the width of the plate tumblers to permit the key operable tumblers to be raised andlowe'red as required by the insertion and withdrawal of the key.

When the key is removed, the key operable tumblers block inward movement of the auxiliary tumblers and thus positively ,hold the same in their operative positions, effecting interengagement between the cylinder and casing.

To free theauxiliary locking tumblers or looking members for inward movement and thereby free the cylinder -for rotation ll i s casing, the key operable tumblers are retractable by a proper key to'u'nlocked positions at which annular grooves 28 in the pin type tumblers and notches 29 in the plate type tumblers are aligned with the inner edges of the auxiliary tumblers or locking members.

When all of the tumblers are so moved to their inoperative positions by a proper key and all of their grooves or notches 28 and 29 respectively, align with the auxiliary tumblers or looking members, it is possible to turn the cylinder as the rounded outer edges of the auxiliary tumblers or looking members cam themselves out or their respective grooves 23 in the casing, the inner edge portions of the locking members entering the grooves or notches in the tumblers.

The annular grooves or notches in the tumblers are of sumcient depth to allow the full inward projection oi the auxiliary tumblers on looking members necessary to release the cylinder for rotation, but have their sides sharply defined so that if an improper key is used, and any one tumbler is not moved to its proper inoperative position, such tumbler will hold the auxiliary tumblers or locking membersin their operative positions. It is thus extremely difllcult, if not utterly impossible, to pick the lock of this invention.

To further guard against the possibility oi. picking, the tumblers are equipped with false grooves and notches 28' and 29'. These false notches and grooves are of insufllcient depth to I allow the complete retraction tumblers or locking members. i

If desired, certain of the tumblers may be equipped with two proper or suiiiciently deep grooves or notches, as shown in Figures 6 and 12, for the purpose of master keying a series of locks, and in Figure 8, the master or special key I3 is shown holding two of the tumblers at (tiifierent heights, but in proper unlocking posiions.

From the foregoing description taken in connection with the accompanying drawing, it will be readily apparent to those skilled in the art to which this invention appertains, that the look here disclosed, aifords a very secure manner of locking the cylinder against rotation in its casing, and that picking or decoding of the lock by any known method is precluded.

What I claim as my invention is:

1.. In a look, a bored mounting member, a lock cylinder movable therein and having transversely extending tumbler guideways, a plurality of key operable tumblers guided at their sides in said guideways for linear movement transversely of the cylinder, and an auxiliary tumbler movable in a plane angular to the plane of movement 01 said plurality of key operable tumblers biased to an operative position interlocking the cylinder and its mounting member and positively held in its operative position by the unimpaired oi the auxiliary thickness of any one of said plurality of key tumbler guideways, a plurality of key operable tumblers guided and supported in the guideways for movement transversely of the cylinder in substantially a common plane longitudinal to the cylinder and with one end of the tumblers accessible from the keyway to be engageable. by v a key inserted into the keyway, spring means acting on the other ends of the tumblers to press the same toward the keyway, a pair of diagonally opposed locking members movable radially in recesses in the cylinder at opposite sides of the plurality of key operable tumblers and engageable by the key operable tumblers at their inner edges, spring means to project the locking members outwardly from the cylinder into engagement with longitudinal grooves in the mounting member to secure the cylinder against rotation, the outer edges of the locking members and the grooves receiving the same being so shaped as to cam the locking members inwardly upon rotation of the cylinder when said key operable tumblers are not blocking inward movement of the locking members, and the key operable tumblers being formed with narrow portions adapted to be aligned with the locking members to receive their inner edge portions and allow in-- ward movement thereof upon movement of the tumblers to unlocked positions by a proper key inserted into the keyway.

SAMUEL A. KISS. 

